Topic: 3.0 manifold-back exhaust

[AlaskaToy]

I am working on an antiwrap setup for my front axle.  Well, it is just one of the bazillion things on my list to do.  When I started looking at where to mount the shackle, I decided I wanted it where the stock exhaust down tube was.  Now rerouting the exhaust and installing my 2.5" Magnaflow muffler is another item on my list, but until now, it was a low priority.  So now I have to move it to the top of the list to facilitate mounting up the antiwrap crap. 

It just so happens, a friend of mine recently installed a cat-back setup on his F150.  Me being a scrounge, I took all his stock crap and leftover Flowmaster kit parts off his hands. This has worked out fairly well since my stock tube was some funky size under 2"; I ended up with some quality 2.25" (or 2.5"?  I can't figure out if I'm suppeosed to measure ID or OD) tube and assorted bends for nothing.  Of course nothing is free, and neither is this project:  My wife convinced me to run a cat, so I got a 2.25" unit from Summit.  The Ford tail pipe has jsut the right bend and length to be the start of my system.  I hacked the flange off my down tube and welded the section of Ford tailpipe to it.  Another peice is melted on now and tommorrw, the cat goes on.  I'm working my way back.  The system will end up 2.25 from the stock manifold to the cat and then 2.5" from there to the muffler and tail pipe.

couple progress pics...

shortened behind-the-cat hanger to get the cat closer to the frame and keep it tucked up higher while still clearing the FRORFab x-member.


From the manifold to the cat...


O2 sensor bung and sensor xferred over.  New cat.

[AlaskaToy [OP]]

way better 'tucked-in" than stock:

[Duffil]

  how do you turn your truck on it's side like that?? Looks like it could be handy for workin on it.

[AlaskaToy [OP]]

how do you turn your truck on it's side like that?? Looks like it could be handy for workin on it.

That's what I thought too, at first.  It turns out it's a real pregnant dog getting the creeper to stay put!

[AlaskaToy [OP]]

Cat-back pics:






This setup is very quiet.  Much quieter than I anticipated.  I like it.

[AlaskaToy [OP]]

The paint is simply rustoleum grill/barbeque paint. I noticed today, it looks fine after running the truck back an forth to work except for the weld locatioins. At the welds the paint is all bubbled and peeling. I assume one of two causes: 1. I simply did a poor prep job around the welds before painting. or 2. The welds are hotter due to more metal in that area and as a result, is retaining more heat, causing the paint to blister and peel. Hopefuly it's the former; I can reprep and repaint when I eliminate the x-over pipe behind the engine.

[CTENG in KS]

You could try that black hi heat paint that bakes on...paint it, then run the truck within 8-hrs of painting to heat cure it.  Same flat black color, would survive the welding better.

[AlaskaToy [OP]]

x-over pipe eliminated...

[AlaskaToy [OP]]

well, I don't detect any extra or lost power, not that I had any before anyway. Stock, I had 28" tires and 4.30 gears. Now I have (temporary, thank God) 4.10s and 35s so I'm dealing with gutlessness no matter what. I do like knowing #6 isn't getting all that extra hot air in its face now.

For anyon who is less cheap than me, I'd recommend using 2" form the manifold to the Y, then 2.5" from there to the Cat and muffler. Then 2.5 or 3" for the tailpipe.

Thanks for reading.

[jeremiah]

That is an awesome setup coming form the manifolds.  I was thinking of this the other day.  I had a truck that ran the downey manifolds but they were a pain to get on and around.  You could pull these off with from underneath if you had to.  Would you be interested in building another manifold to Y setup?

Good job, very clean.

Jeremiah

[BLACKDOG]

Ok, that is a freakin awesome idea!!  I hate running that crossover, but I gotta pass Cali smog     wonder if I could get away with using that anyway?  of course, I could run it and keep the crossover for the trst every two years

How does it do clearance wise?  where did the y wind up?

[AlaskaToy [OP]]

Thanks for the compliments.

The scoop:  the heat transfer to the pass side floorpan is out of hand.  I am worried I'd boil fuel or worse at slow speed wheeling.  I whipped out a heat shield this morning, but I don't think it is enough.  I really think I should have run the exhaust wrap righ up to the flange. 

Any way, here are some pix of the setup mounted....

[Plowking]

I like that better than what Downey offers, I am worried about the fuel line as well it runs right next to the header on the passenger side. Looks pretty sweet.

[kneedownnate]

Between the header wrap and installing some of the reflective heat shield on the fuel line you should be ok. 

The thicker metal at the welds should actually be cooler, cause there's more metal to dissipate the heat.  You do hafta clean the welds and surrounding areas really well and slap on more paint though, but no matter what it's probably gonna rust through anyway.  Ever tried VHT?  Motorbike or paint shops should carry it.  It's made to handle crazy temps.

[BLACKDOG]

Anyway you can get a temp reading of that pass. side floor pan?  tape a thermometer to it or something?    Do you have a body lift?  I was out looking at my truck the other day, and I think with the 3" body lift that I have, I may be able to run a pipe over the tranny, between the shifter and the bellhousing.    If I can't get it cool enough though, I don't want to do it.  I'm gonna look more into this idea of yours, I really like it

[AlaskaToy [OP]]

Purely anecdotal (I could get a temp of the floor pan, but I am too lazy to dig thru my nitro r/c stuff to find the IR thermometer)  I'd gues it was well over 200 degrees.  Since, I have tweeked the heatshield brackets some to get the shield closer to the pipe and further from the floorpan/firewall.  I also added a small section of thermotec adhesive backed radiant heat shield and put some on the exterior in the hottest felt area. 

Today, driving around and checking periodically, the temp never got more than warm to the touch.  I would be even better off pulling the whole exhaust and putting the thermotec stuff up the entire firewall directly behind the downpipe, but this will do just fine. 

I did some minor tweeking of the fuel lines as well.  Much more comfortable now.

[BLACKDOG]

I may have to give this a shot.     I've gotta get moving on my exhaust, didn't realize how bad it was leaking until I put my full doors up.  can't drive with the windows up   need to pass smog too